Handles VP8, VP9 and AV1
WebM files use the VP8, VP9 or AV1 video codecs, which MP4 does not carry. This tool transcodes the video to H.264 so it plays everywhere, the standard way to convert WebM to MP4.
Free WebM to MP4 converter · Runs in your browser
Convert WebM to MP4
Free & Private
Turn a .webm (VP8, VP9 or AV1) into an .mp4, quickly, without uploading it.
Private, nothing leaves your device No sign-up100% free
Drag & drop a WebM (or MOV, MP4, MKV) file, or click to browse
Choose fileTurn a .webm video into a universally-playable .mp4 right in your browser. Drop in the file and it is converted on your own device, free, with no sign-up, no watermark and nothing uploaded to a server.
- Convert WebM to MP4
- WebM screen recording to MP4
- WebM to MP4 for editing
- Play a WebM on iPhone
- WebM to MP4 for social media
- Downloaded WebM to MP4
Private
The video is converted on your device, never uploaded
Fast
Hardware-accelerated WebCodecs transcode in your browser
Free
No account, no size-limit tricks, no watermark
Three steps
How it works
Upload your WebM
Drag in or choose a .webm file (or any video). It stays on your computer, and nothing is sent anywhere.
We convert it to MP4
The video is transcoded to H.264, the codec MP4 uses, with the browser’s hardware-accelerated WebCodecs. No server round-trip, no queue.
Play & download the MP4
Preview the result, then download the .mp4, ready to play on any phone, upload anywhere, or drop into any editor.
Built for creators
Why people choose it
Hardware-accelerated in your browser
The conversion runs on the browser’s built-in WebCodecs pipeline, the same hardware-accelerated technology professional web video tools use, so a WebM-to-MP4 conversion is fast and stays on your machine.
100% private
The whole conversion happens on your own device. Nothing is uploaded and no account is needed. Safe for screen recordings, personal clips and client work.
No size paywall or watermark
Because it runs locally there is no per-file charge and no branding stamped on your video. Bigger files simply take a little longer to transcode.
Plays where WebM won’t
MP4 (H.264) is the most compatible video format there is: iPhones, most editors and many upload forms accept MP4 but reject or refuse to play a .webm. Converting fixes that.
Nothing to install
It is a web page, not an app. Open it, drop a WebM in, and get an MP4, and it works in Chrome and Edge on desktop, with no download or extension.
How to convert WebM to MP4 for free
WebM is a web-first video format, and you get it from screen recorders, downloaded clips and some browser exports. It plays fine in a desktop browser, but it is awkward elsewhere: iPhones, plenty of editors and many upload forms expect an MP4 instead. Converting WebM to MP4 fixes that: the file just plays and uploads. Drop your .webm onto this tool and it hands you an MP4, right in the browser.
Because a WebM uses the VP8, VP9 or AV1 codec and MP4 uses H.264, this is a true transcode rather than a simple rewrap: the tool decodes the WebM and re-encodes it to H.264 using the browser’s hardware-accelerated WebCodecs. That keeps the whole WebM-to-MP4 conversion on your machine and reasonably fast, with no upload and no server queue.
Convert WebM to MP4 without uploading anything
Typical online converters make you upload your video to their servers, wait, then download the result, which is slow, and a privacy problem for personal recordings. This WebM to MP4 converter is different: everything runs on your own device. Nothing is uploaded, there is no account, and there is no watermark on the finished MP4.
It is the easy way to turn a WebM screen recording into an MP4, get a downloaded .webm to play on an iPhone, or prepare a clip for an editor that will not accept WebM. It also accepts MOV, MP4 and MKV if you need to normalise those to a standard MP4 as well.
Quality and honesty
Unlike an already-H.264 file, a WebM can’t be losslessly copied into an MP4: its codec is different, so re-encoding is unavoidable. The tool uses a high-quality H.264 encode so the result looks essentially identical for normal viewing. We keep it honest: if a file genuinely can’t be converted in the browser, the tool tells you rather than producing a broken MP4.
How it compares
A free, private alternative to online converters
Most "WebM to MP4" sites upload your video to a server, queue it, and cap or watermark the free tier. This tool does the conversion on your own machine.
Your fileUploaded to their serversNever leaves your device
Sign-upOften requiredNone
Size / length capLimited on free tierBounded only by your device
WatermarkSometimesNone
PrivacyFile leaves your machineFully local
CostFreemium / paidFree
Questions
Frequently asked questions
How do I convert a WebM to MP4 for free?
Drop your .webm file onto the tool and click Convert to MP4. It transcodes the video in your browser and lets you download the .mp4, free, with no sign-up and nothing uploaded.
Is converting WebM to MP4 lossless?
No, and no tool can make it lossless. WebM uses VP8/VP9/AV1 while MP4 uses H.264, so the video must be re-encoded. This tool uses a high-quality H.264 encode, so for normal viewing the result looks essentially the same.
Why won’t my WebM play on my iPhone or in my editor?
WebM is a web-oriented format that iPhones and many editors don’t support. Converting it to MP4 (H.264), the universal video format, makes it play and upload everywhere.
Is my video uploaded to a server?
No. The conversion runs entirely on your own device and the MP4 is built in your browser. Nothing is uploaded and no account is needed, so it is safe for private recordings.
Does it support VP9 and AV1 WebM files?
Yes, as long as your browser can decode them. Chrome and Edge decode VP8, VP9 and AV1. The tool decodes the WebM and re-encodes it to H.264 for the MP4.
Is there a file-size limit?
There is no artificial cap. Because conversion happens in memory on your machine, very large files are bounded by your device’s available memory, and transcoding a big file takes longer.
Does the MP4 have a watermark?
No. There is no watermark and no branding added to your video. The output is a clean MP4.
Which browsers does it work in?
It works in modern desktop browsers with WebCodecs. Chrome and Edge are the most reliable for WebM decoding. The whole conversion is client-side, so no install is needed.
Keep going
More free browser tools
Convert your first WebM to MP4
Drop in a .webm and download a standard MP4 in your browser, free, private, and with no account.
Runs entirely in your browser. Your files never leave your device.
